It’s not the ‘chicken or the egg’ dilemma but two very different situations. Gestational diabetes, which occurs in 3-20 per cent of pregnant women, is a type of diabetes that develops during pregnancy.
By Shelley Diamond, BScPhm
Illustration by Martin Bregman
Although blood glucose levels return to normal after delivery, someone who develops gestational diabetes has a higher risk for developing type 2 diabetes later in life.
Women with pre-existing diabetes who plan to get pregnant have specific monitoring recommendations to ensure they have a healthy baby. This article focuses on ‘pre-gestational diabetes,’ where you have an important role in counselling women with type 1 or type 2 diabetes who are planning to start a family.
Diabetes and pregnancy
Women with diabetes should maintain target blood glucose levels as much as possible since elevated glucose during pregnancy can lead to complications for the fetus. These include fetal malformations if glucose is elevated at conception and in the first trimester, or macrosomia (excessive birth weight) or metabolic complications at birth, if glucose is increased later in pregnancy.
Preconception care has been associated with better health outcomes, so it is important for pharmacists to ensure that women with diabetes who are planning pregnancy meet with their diabetes healthcare team to discuss how to achieve tight glycemic control. This team may include diabetes nurse educators, dietitians, obstetricians and diabetologists (specialists in diabetes).
Key messages you can share with women with type 1 or type 2 diabetes preconception include:
- The importance of reaching blood glucose targets before pregnancy (aim for a preconception A1C ≤7.0% or an A1C as close to normal as can safely be achieved).
- The impact of BMI on pregnancy outcome (obesity increases morbidity and mortality for both mother and baby).
- A supplement of folic acid 5mg daily at least three months pre-conception and continuing for at least 12 weeks post-conception should be recommended. A multivitamin with 0.4-1.0mg folic acid should be continued from 12 weeks post-conception to at least six weeks postpartum or as long as breastfeeding continues.
- Discontinue medications that are potentially embryopathic, such as ACE inhibitors, ARBs or statins.
- Women with type 2 diabetes who are using non-insulin medications should switch to insulin for glycemic control (those with PCOS should continue using metformin for ovulation induction).
Management during pregnancy
Women with type 1 or type 2 diabetes should receive intensive insulin therapy that is individualized along with their glycemic targets. Generally the following targets are recommended:
Fasting plasma glucose <5.3 mmol/L
1-hour postprandial glucose <7.8 mmol/L
2-hour postprandial glucose <6.7 mmol/L
Additional recommendations include:
- Ophthalmological assessments should be done before conception, during the first trimester, as needed during pregnancy, and within the first year postpartum because of increased risk of progression of retinopathy with pregnancy.
- Blood pressure should be assessed regularly and managed with medications known to be safe during pregnancy, such as calcium channel blockers, labetalol and methyldopa.
- Women should be screened for chronic kidney disease pre-conception, as well as monitored during pregnancy since it is associated with an increased risk of maternal and fetal complications.
- Although it is rare, women with known cardiovascular disease should be counselled regarding the risks during pregnancy.
- SMBG should be done both pre- and post-prandially.
- Women need to be monitored for hypoglycemia postpartum since the risk is increased.
- Metformin and glyburide can be used during breastfeeding.
- Women with type 1 diabetes should have a thyroid test (TSH) at six-eight weeks postpartum to screen for thyroiditis.
- For women who are obese, breastfeeding is important since this may actually offset the risk of obesity for their child.
Hopefully after the birth of a new healthy baby, your role continues as you advise this group of women on appropriate contraception, nutritional management, continued glycemic control, and sometimes sooner than later – future pregnancy planning!
Shelley Diamond BScPhm is the president of Pedipharm Consultants and Diabetes Care Community Inc. (www.diabetescarecommunity.ca)